Medical image recording device

ABSTRACT

A medical image recording device includes an image pickup device generating an image pickup signal by photoelectric ally converting light reflected from a subject with use of an image pickup element, wherein an image pickup control unit displays, on a display unit, image data generated for each of frames constituting a video by processing the image pickup signal. A recording control unit records the image data on a memory card. A movement detection unit sequentially compares the image data between the adjacent frames, and calculates an amount of movement of the image pickup device from a positional shift of a main subject between the adjacent frames. If the amount of movement is within a preset range, a camera shake correction unit corrects a blur. If the amount of movement is greater than an upper limit of the range, the recording control unit stops recording of image data on the memory card.

TECHNICAL FIELD

The present invention relates to a medical image recording device thatshoots pictures of treatment when medical treatment is carried out inorder to record.

BACKGROUND ART

Putting an image pickup device, such as a digital video camera equippedwith image pickup elements of CCD or CMOS type, on the body of anoperator who carries out an operation in order to shoot a video of howthe operation is going is a common practice.

In particular, in the field of medical treatment, if a video of how anoperator has conducted an operation on a treatment target location istaken and left as a record, the video will be highly useful asexplanatory material when a person who got the treatment or his/herfamily receives an explanation of how the operation is conducted afterthe operation, or as material for academic conferences or medicaleducation.

In order to meet such needs, what is known is a medical image pickupdevice whose image pickup device is attached to a binocular loupe orheadband that an operator puts on his/her head or face when conductingan operation, enabling the image pickup device to shoot a treatmenttarget location the operator is closely watching (Refer to PatentDocuments 1 and 2, for example).

However, when the image pickup device is used to shoot a subject withinan image pickup range, so-called “camera shake” is a problem. The“camera shake” means that the movement of the body or head of theoperator shakes the image pickup device during medical treatment,causing the video to blur. Delicate work, such as medical treatment,entails wiggling of hands. If the image pickup device that is put on thebody of the operator moves when a shutter is being opened, the movementcauses the video to blur, thereby making the video unclear.

In order to suppress such a camera shake, what is known is a digitalcamera that uses an acceleration sensor, or detects an image shiftbetween two consecutive frames of the video, in order to obtaincamera-shake information and correct the image data to correct thecamera shake (Refer to Patent Document 3, for example).

PRIOR ART DOCUMENTS Patent Documents

[Patent Document 1] Japanese Patent Application Laid-Open PublicationNo. 2003-204972

[Patent Document 2] Japanese Patent Application Laid-Open PublicationNo. 2009-98570

[Patent Document 3] Japanese Patent Application Laid-Open PublicationNo. 2009-77265

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, in the case of an image pickup recording device that leaves animage pickup result as a record, besides blurred images caused by a“camera shake” or the like, the video becomes inappropriate as a recordvideo once a subject that should be shot and left as a record goes outof a shooting target. That is, in the case of a medical image pickupdevice that is put on the head or face of an operator to shoot atreatment target location that the operator is closely watching duringmedical treatment, for example, if the operator turns his/her face awayfrom the treatment target location as the operator gives a treatmentassistant instructions or the like during the treatment or the operatorslightly moves his/her body to relax during a long medical treatmenttime, the image pickup device takes an image of locations other thanwhere the treatment is carried out, and the record video becomesdefective as the record video contains that image. In this case, it isannoying for the operator to operate a release switch for video shootingeach time the treatment is suspended. It is also difficult for theoperator to do the operation because the blood or body fluid of apatient adheres to his/her hands and fingers.

In view of the above problems, the object is to provide a medical imagerecording device that can save a good record video by stopping, when ashooting direction of an image pickup device is moved in such a way thatan image moves away from a subject (treatment target location),recording of the captured image of a portion thereof.

Means for Solving the Problems

To solve the above problems a medical image recording device that shootsby putting, on a body of an operator conducting medical treatment, animage pickup device that includes at least an optical lens and an imagepickup element which generates an image pickup signal byphotoelectrically converting light introduced from a subject via theoptical lens during shooting, includes: an image pickup control unitthat controls in such a way as to display, on a display unit, a videofrom image data that is generated for each of frames that constitute thevideo based on the image pickup signal; an information recording unitthat sequentially records the image data; a movement detection unit thatsequentially compares the image data between consecutive or adjacentframes, and calculates an amount of movement of the image pickup devicebased on a positional shift of a main subject between the frames; acamera shake correction unit that corrects, when the amount of movementis within a preset range, a positional shift of the video caused by themovement corresponding to the amount of movement; and a recordingcontrol unit that controls stopping of the recording of the image dataon the information recording unit when the amount of movement is greaterthan an upper limit of the range. Accordingly, it is possible to stopthe recording of the image data by detecting a change in the directionof the shooting by the image pickup device through image recognition.

At this time, the image pickup control unit stops, when the amount ofmovement is greater than the upper limit of the range, the displaying ofthe video. In this case, the image pickup control unit may stop thedisplaying of the video after a predetermined time-lag period has passedsince the movement detection unit detects that the amount of movementexceeds the upper limit of the range.

The image pickup control unit controls in such a way as to display, as astill image, the image data that appears before the movement becomesgreater than or equal to the upper limit of the range, after thedisplaying of the video is stopped. In this case, the image pickupcontrol unit may control in such a way as to display the still imageafter a predetermined time-lag period has passed since the movementdetection unit detects that the amount of movement exceeds the upperlimit of the range.

After the amount of movement exceeds the upper limit of the range andafter a main subject detected by the movement detection unit has come toresemble the main subject that appears before the amount of movementexceeds the upper limit of the range, the recording control unitcontrols resumption of the recording of the image data by theinformation recording unit, and the image pickup control unit controlsresumption of the displaying of the video.

Meanwhile, if the amount of movement is within the range, the movementis recognized as a camera shake, and the camera shake correction unitgenerates corrected image data by combining the image data of aplurality of consecutive or adjacent frames.

A medical image recording device of the present invention that shoots byputting, on a body of an operator conducting medical treatment, an imagepickup device that includes at least an optical lens and an image pickupelement which generates an image pickup signal by photoelectricallyconverting light introduced from a subject via the optical lens duringshooting, includes: an image pickup control unit that controls in such away as to display, on a display unit, a video from image data that isgenerated for each of frames that constitute the video based on theimage pickup signal; an information recording unit that sequentiallyrecords the image data; an acceleration sensor that detects movement ofthe image pickup device; a first movement detection unit that calculatesan amount of movement of the image pickup device based a detectionsignal of the acceleration sensor; a camera shake correction unit thatcontrols in such a way as to cancel a blur in the video caused by themovement corresponding to the amount of movement calculated by the firstmovement defection unit; a second movement detection unit thatsequentially compares the image data between consecutive or adjacentframes, and calculates an amount of movement of the image pickup devicefrom a positional shift of a main subject between the frames; and arecording control unit that controls stopping of the recording of theimage data when the amount of movement calculated by the second movementdetection unit is greater than or equal to a preset threshold value.

Advantages of the Invention

In the medical image recording device of the present invention, when theimage pickup device has captured an image that is not directly relatedto an operation of treatment, the image is not recorded on the recordingdevice. Therefore, the operator does not have to turn off the shootingof the image pickup device every time. A valid record of treatment canbe saved only by putting the image pickup device on the body of theoperator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing, as blocks, the configuration of a medicalimage recording device according to a first embodiment of the presentinvention.

FIG. 2 is an explanatory diagram of a binocular loupe that includes animage pickup device and an illumination unit.

FIG. 3 is an explanatory diagram of a head band that includes an imagepickup device and an illumination unit.

FIG. 4 is an explanatory diagram showing an example in which a medicalimage recording device of an embodiment of the present invention is puton an operator.

FIG. 5 is an explanatory diagram showing a control unit of a medicalimage recording device of an embodiment of the present invention.

FIG. 6 is a diagram showing, as blocks, electric circuits of a medicalimage recording device according to a second embodiment of the presentinvention.

FIG. 7A is an explanatory diagram schematically showing an image of eachframe in a medical image recording device according to the firstembodiment of the present invention; FIG. 7B is an explanatory diagramschematically showing image data recorded on a memory card.

FIG. 8A is an explanatory diagram schematically showing an image of eachframe that comes after those of FIGS. 7A and 7B in a medical imagerecording device according to the first embodiment of the presentinvention; FIG. 8B is an explanatory diagram schematically showing imagedata recorded on a memory card.

FIG. 9A is an explanatory diagram schematically showing an image of eachframe in a medical image recording device according to the secondembodiment of the present invention; FIG. 9B is an explanatory diagramschematically showing image data recorded on RAM; FIG. 9C is anexplanatory diagram schematically showing image data recorded on amemory card.

FIG. 10A is an explanatory diagram schematically showing an image ofeach frame that comes after those of FIGS. 9A-9C in a medical imagerecording device according to the second embodiment of the presentinvention; FIG. 10B is an explanatory diagram schematically showingimage data recorded on RAM; FIG. 10C is an explanatory diagramschematically showing image data recorded on a memory card.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, optimal embodiments of the present invention will bedescribed with reference to the accompanying drawings.

First Embodiment

FIG. 1 is a block diagram showing the schematic configuration of amedical image recording device according to a first embodiment of thepresent invention.

An image pickup device 1 is a digital video camera that shoots a video.The image pickup device 1 includes an optical lens 2, which allows lightto enter from a subject during shooting; an image pickup element 3,which includes CCD or CMOS to generate image signals byphotoelectrically converting the reflected light coming from the subjectvia the optical lens 2 into analog electric signals; an accelerationsensor 4; an image pickup element displacement mechanism 5; and a lensadjustment mechanism 6.

The acceleration sensor 4 detects a “camera shake”. For example, athree-axis type is used. The acceleration sensor 4 detects, asacceleration, angular velocities of movements in three-axis directionsof X, Y, and Z, which are perpendicular to each other with the axis ofthe operator's neck, as center. After carrying out such processes as A/Dconversion, the acceleration sensor 4 outputs a detected signal to CPU10.

The image pickup element displacement mechanism 5 prevents the videofrom blurring due to the “camera shake” by moving the image pickupelement 3 based on an amount of movement of the image pickup device 1,which is calculated from acceleration detected by a movement detectionunit 10 b described later.

The lens adjustment mechanism 6 uses a built-in drive motor to move theoptical lens 2, thereby carrying out focusing and zooming. Incidentally,although not shown in the diagram, the optical lens 2 includes adiaphragm mechanism; the aperture is adjusted by driving of the drivemotor, thereby adjusting the intensity of the subject light entering theimage pickup element 3.

A signal processing unit 7 amplifies an image signal that is input fromthe image pickup element 3, converts the image signal into a digitalsignal, and outputs the digital signal to the CPU 10. In the medicalimage recording device of the present embodiment, the video of a subjectis shot at a rate of 30 frames per second, for example. Therefore, thesignal processing unit 7 generates image data of each frame, and outputsthe image data to the CPU 10. The function of generating image data ofeach frame may belong to the CPU 10.

An operation unit 8 includes a power switch, which is used to turnON/OFF the supply of power to the image pickup device 1, a releaseswitch, which starts the shooting of video, and a zoom switch, which isused to conduct a zooming operation of the optical lens 2.

A memory card 9, which is used as an information recording unit, recordsimage files of the video transmitted from the CPU 10 via an interface 9a and outputs the recorded image files to the CPU 10. The image filesare recorded in Motion JPEG format. The images of each frame arecompressed in JPEG and successively combined. The information recordingunit can use not only a memory card but also various recording media,such as various disc or memory types.

A display unit 13 includes a display panel 13 a (FIG. 5), which is aliquid crystal panel or an organic EL panel. The display unit 13displays the video shot by the image pickup device 1. The display unit13 is also used to play and display the video of image files stored inthe memory card 9.

An illumination unit 15 is used to secure the brightness of a treatmenttarget location (subject). For example, the illumination unit 15includes a plurality of LED elements that emit the light of each color.The illumination unit 15 is supplied with drive power from anillumination drive unit 14. In this case, it is preferred to avoid blueLED elements of a 400 nm to 500 nm band, which is said to hurt eyes.

RAM 12 is SDRAM, which is capable of high-speed reading and writing ofdata, for example. On the RAM 12, the image data output from the signalprocessing unit 7, and data being processed by the CPU are temporarilyrecorded.

The CPU 10 controls operation of a medical image recording device basedon control programs and various setting data, which are written to theROM 11, and how each of the various switches of the operation unit 8 isoperated. By executing the control programs, the CPU 10 functions as: animage pickup control unit 10 a; a movement detection unit 10 b, whichcalculates an amount of movement of the optical lens 2 or image pickupelement 3; a camera shake correction unit 10 c; a compression anddecompression processing unit 10 d; a recording control unit 10 e; aplayback control unit 10 f; an illumination control unit 10 g; and thelike.

Each control function of the CPU 10 will be described.

The image pickup control unit 10 a controls, based on a switch operationof the operation unit 8, the driving of a motor contained in the lensadjustment mechanism 6 to carry out an auto focus process, a zoomingprocess, and an exposure adjustment process, thereby controlling theshooting of a video of a subject by the image pickup device 1. The imagepickup control unit 10 a also performs image processing, such as whitebalance adjustment, color interpolation processing, and aberrationcorrection processing, on the image data of each frame transmitted fromthe signal processing unit 7.

Although not shown in the diagrams, the movement detection unit 10 bfunctions as a first movement detection unit, which detects a “camerashake” based on a detection signal supplied from the acceleration sensor4, and as a second movement detection unit, which uses image recognitionof a subject recognition unit 101 b to detect that the shooting of theimage pickup device 1 has shifted from the treatment target location.The subject recognition unit 101 b is part of the functionality of themovement detection unit 10 b, which is realized by a control programprocess of the CPU 10. For example, the subject recognition unit 101 bmay be a subroutine, function, procedure, or the like. The subjectrecognition unit 101 b analyzes the images of image data, betweenconsecutive or adjacent frames that the image pickup control unit 10 areceives from the signal processing unit 7. Then, the subjectrecognition unit 101 b extracts the contours of the subject as featurepoints, and recognizes an area where the feature points overlap; withone another as a main subject. In this case, each of images betweenframes that are adjacent to each other at intervals of 1/30 seconds, oreach of images between frames that, are close to each other, forexample, at intervals of 1/3 seconds is sequentially analyzed, and acommon portion is recognized as a main subject.

The first movement detection unit of the movement detection unit 10 bcalculates, from acceleration components of X, Y, and Z that are outputfrom the acceleration sensor 4, the amounts of movement of the imagepickup device 1 in a left-right direction (X-direction), an up-downdirection (Y-direction), and a front-back direction (Z-direction). Thecamera shake correction unit 10 c carries out control in such a way asto correct a career a shake by operating the image pickup elementdisplacement mechanism 5 based on the amounts of movement calculated bythe first movement detection unit.

Meanwhile, the second movement detection unit of the movement detectionunit 10 b identifies the movement of the shooting direction of the imagepickup device 1 by detecting a change of the main subject recognized bythe subject recognition unit 101 b. During this process, the movementdetection unit 10 b calculates a value of a positional shift in thevertical and horizontal directions on X-Y axes of the main subject ineach of the images between frames that are adjacent to each other or ineach of the images between frames that are close to each other. If thevalue of the positional shift calculated exceeds a preset thresholdvalue, the movement detection unit 10 b then judges that the mainsubject has been changed as the shooting direction of the image pickupdevice 1 moves away from the treatment target location, and that thetreatment is suspended.

The compression and decompression processing unit 10 d compresses, inJPEG, the image data of each frame loaded onto the RAM 12, therebygenerating an image file of the video to be recorded on the memory card9. When the video of an image file recorded on the memory card 9 isplayed, the compression and decompression processing unit 10 ddecompresses the compressed image data.

The recording control unit 10 e controls the process of writing theimage data, which has been compressed in JPEG for each frame, to thememory card 9.

The playback control unit 10 f reads images stored in the memory card 9to display the images on the display unit 13.

The illumination control unit 10 g outputs a control signal to theillumination drive unit 14 in order to supply drive power to theillumination unit 15 and control the amount of current thereof.

An example of how the image pickup device 1 is put on the body of anoperator will be described. In the example shown in FIG. 2, the imagepickup device 1 and the illumination unit 15, which casts light on asubject, are attached to a binocular loupe 20 that an operator puts onhis/her face when conducting treatment. Instead of the binocular loupe20, a cap or a headband may be used. FIG. 3 shows a headband 21 to whichthe image pickup device 1 and the illumination unit 15 have beenattached. The headband 21 is made of a resin member; the headband 21 iskept and fixed on the head of an operator due to the elasticity thereof.The headband 21 is not limited to this configuration. The headband 21may be made of cloth, rubber, or the like, and can be made in variousforms.

As shown in FIGS. 4 and 5, the operator wraps a battery holding belt 22around his/her waist; a battery power source is held by the batteryholding belt 22 as an operation power source for this medical imagerecording device. The battery power source includes a plurality ofrechargeable batteries 16, which are connected to each other. Thebattery holding belt 22 includes mounting sections 28 into which thebatteries 16 are inserted in a detachable manner. On the battery holdingbelt 22, a control unit 24 is mounted along with the batteries 16. Thebatteries 16 are connected to the control unit 24.

On the surface of a unit casing of the control unit 24, the operationunit 8 and the display panel 13 a of the display unit 13, which is aliquid crystal panel or an organic EL panel, are disposed. The displaypanel 13 a is used as a monitor screen for captured images. Anotherdisplay panel 13 b is provided so that nearby people, such as treatmentassistants, can monitor how the treatment is going on. In this case, ifsignals of the image data are transmitted wirelessly from the controlunit 24 to the display panel 13 a, the operator can move freely duringthe treatment.

If a Wi-Fi network camera is used as the image pickup device 1, thevideo can be fed to a terminal device with a display panel 13 b via theinternet so that the monitoring is possible. In this case, in theterminal device, the URL of the network camera is specified on a WEBbrowser. Therefore, the terminal device can take in the images capturedby the network camera of how the treatment is being carried out via theinternet in real time. In this manner, the upside of using a wirelessLAN is that the treatment can be monitored in real time through terminaldevices at any locations other than where the treatment is carried out.

On a side surface of the unit casing, a slot 30, into which the memorycard 9 is inserted in a detachable manner, is formed. A control board onwhich the CPU 10, the ROM 11, the RAM 12, the signal processing unit 7,and the display unit 13 are mounted is housed inside the unit casing.

A cable harness 25 is a bundle of: a power cord, which supplies drivecurrent from the control unit 24 to the image pickup device 1 and theillumination unit 15; signal lines of control signals, which are outputfrom the CPU 10 to the image pickup element displacement mechanism 5 andthe lens adjustment mechanism 6; and an input signal line, which extendsfrom the acceleration sensor 4 to the CPU 10.

If a charger 26 whose plug is plugged into an electrical outlet 27 isconnected to the control unit 24, the image pickup device 1 and theillumination unit 15 can be used to carry out a shooting operation andan illumination operation when the batteries 16 are being charged.Therefore, the video can be shot even during a prolonged treatment.

The operation of the above medical image recording device will bedescribed. When the operation unit 8 of the control unit 24 is operatedto turn the medical image recording device ON, the CPU 10 loads thecontrol programs onto the ROM 11 to initiate the operation of themedical image recording device. At this time, if the operator directshis/her face at a subject or a treatment target location, the imagepickup control unit 10 a carries out an auto focus process and anexposure adjustment process for the subject. When a zooming switch ofthe operation unit 8 is operated, the image pickup control unit 10 aadjusts the zooming of the optical lens 2. The illumination control unit10 g controls the illumination drive unit 14 and turns the illuminationunit 15 ON by supplying drive current to the illumination unit 15 insuch a way that a normal level of brightness is secured.

When the release switch of the operation unit 8 is operated, the imagepickup control unit 10 a starts to shoot a video. The image pickupcontrol unit 10 a sequentially takes in image data of each frame fromthe signal processing unit 7 to store the image data in the RAM 12, andcarries out image processing, such as white balance adjustment, colorinterpolation processing, and aberration correction processing, on thestored image data. Then, the image pickup control unit 10 a sequentiallyreads the image data that is stored in the RAM 12 and has undergone theimage processing, and outputs the image data to the display unit 13. Thevideo is displayed on the display unit 13 as a result. As describedabove, the signal processing unit 7's function to sequentially generatethe image data of each frame may be realized by the CPU 10 that executesthe control programs of the ROM 11.

The compression and decompression processing unit 10 d compresses theimage data in JPEG after the image data, stored in the RAM 12, underwentthe image processing. The compressed image data is transmitted to thememory card 9 and recorded in an image file of the video.

FIGS. 7A and 8A schematically show images of image data whose each frameis taken into the image pickup control unit 10 a from the signalprocessing unit 7, when image signals of images taken by the imagepickup device 1 that is put on the head via the above binocular loupe 20or headband 21 are output to the signal processing unit 7 duringtreatment by the operator. The image pickup control unit 10 a actuallytakes in the image data at a rate of 30 frames per second, in order toshoot a video via the image pickup device 1. For ease of explanation, inthe case of FIGS. 7A and 8A, a series of images during the treatment issimplified in such a way as to only show images of representativeframes.

The image pickup control unit 10 a takes in the image data of each framefrom the signal processing unit 7, and stores the image data in the RAM12 without any change. The image pickup control unit 10 a then carriesout image processing, such as white balance adjustment, colorinterpolation processing, and aberration correction processing. Then,the image pickup control unit 10 a sequentially reads the image datathat is stored in the RAM 12 and has undergone the image processing, andoutputs the image data to the display unit 13. The video is displayed onthe display unit 13 as a result.

The compression and decompression processing unit 10 d compresses, inJPEG, each set of the image data sequentially stored in the RAM 12. Thecompressed image data is transmitted to the memory card 9 and recordedin an image file. FIGS. 7A and 8B schematically show the image datarecorded on the memory card 9.

The operation will be described with the use of FIGS. 7 and 8. Thesubject recognition unit 101 b recognizes a main subject from image dataof each frame that the image pickup control unit 10 a sequentiallyreceives from the signal processing unit 7. In the second movementdetection unit of the movement detection unit 10 b, the subjectrecognition unit 101 b sequentially analyzes each of recognized imagesbetween frames that are adjacent to each other at intervals of 1/30seconds, or each of recognized images between, frames that are close toeach other, for example, at intervals of 1/3 seconds, in order tocalculate a positional shift of the main subject. If the main subjectdoes not change significantly between frames being analyzed, or if thecalculated positional-shift value does not exceed the threshold value,it is determined, that the image pickup device 1 keeps shooting the samesubject. To be more precise, the main subject is gradually changing asthe treatment proceeds. Therefore, at the time when the image F3appears, the movement detection unit 10 b recognizes an organ exposed byopening of the abdomen as a main subject, which is significantlydifferent from the main subject recognized when the image F1 appears.

At this time, for example, suppose that the operator suspends thetreatment and turns his/her face to an assistant to give the treatmentassistant instructions. At this time, the image pickup device 1 takes animage of the assistant, and the image pickup control unit 10 a takes ina frame of image F4 from the signal processing unit 7. When the subjecthas abruptly changed in this manner, there is a great shift from themain subject that the movement detection unit 10 b has so far recognizedby sequentially carrying out pattern matching between the frames. Ifthere is a great shift from the main subject, the positional-shift valuecalculated exceeds a present threshold value. Accordingly, the movementdetection unit 10 b judges that the shooting direction of the imagepickup device 1 has moved away from the subject (treatment targetlocation).

As a result, the recording control unit 10 e prohibits the compressionand decompression processing unit 10 d from writing the compressed imagedata to the memory card 9. Therefore, the image F4 of FIG. 7A is notrecorded on the memory card 9 as shown in FIG. 7B. The image pickupcontrol unit 10 a continues the process of storing the image data ofeach frame coming from the signal processing unit 7 in the RAM 12, aswell as the image processing, such as white balance adjustment, on thestored image data. Therefore, even if the treatment is suspended, theimage taken by the image pickup device 1 will be displayed on thedisplay unit 13 and can be monitored. However, when the movementdetection unit 10 b judges that the shooting direction of the imagepickup device 1 has moved away from the treatment target location, theimage pickup control unit 10 a stops the process of storing the imagedata of each frame coming from the signal processing unit 7 in the RAM12, as well as the image processing, such as white balance adjustment,on the stored image data. During a period in which the image pickupdevice 1 is shooting any location other than where the treatment iscarried out, the image pickup control unit 10 a may display, as a stillimage, a previously captured image F3 of the treatment target locationtaken by the image pickup device 1 on the display unit 13.

When the movement detection unit 10 b judges that the shooting directionof the image pickup device 1 has moved away from the treatment targetlocation, the illumination control unit 10 g controls the illuminationdrive unit 14 to halt the supply of power to the illumination unit 15 orreduce the current supplied to the illumination unit 15, therebypreventing the batteries 16 from being consumed.

Even after a drastic change of the main subject caused by the suspensionof the treatment, the movement detection unit 10 b uses the subjectrecognition unit 101 b to keep recognizing the main subject by carryingout a pattern matching process of image data of each frame that theimage pickup control unit 10 a receives from the signal processing unit7, and makes a determination as to whether the recognized main subjectresembles a previous main subject (i.e. treatment target location),which is captured before the positional-shift value exceeds thethreshold value. If the movement detection unit 10 b detects that themain subject recognized by the subject recognition unit 101 b resemblesthe previous main subject, then the movement detection unit 10 b judgesthat the operator has restarted the treatment. As a result, the image F5and other images that come after the restart of the treatment arecompressed by the compression and decompression processing unit 10 d.The compressed image data are sequentially recorded on the memory card 9by the recording control unit 10 e. In this manner, on the memory card9, only image files of video of how the operator is conducting thetreatment are recorded. The illumination control unit 10 g controls theillumination drive unit 14 to restart the supply of power to theillumination unit 15 or bring the amount of current supplied to theillumination unit 15 back to a normal level.

This embodiment, too, has a time-lag period of 0.2 to 0.5 seconds, forexample, as described above. If the operator does not have any intentionto suspend the operation but the operator temporarily turns his/her faceaway from the treatment target location before immediately moving theface back to the treatment target location, an image of a location otherthan where the treatment is being carried out may be taken by the imagepickup device 1 during that short period of time and be displayed on thedisplay unit 13. In such a case, the time-lag period can prevent theimages from being displayed unnaturally. The recording control unit 10 emay wait for the time-lag period to pass before controlling the stop ofwriting of image data to the memory card 9; the illumination controlunit 10 g may wait for the time-lag period to pass before controlling insuch a way as to stop the supply of power to the illumination unit 15 orreduce the current supplied to the illumination unit 15.

When the operator directs his/her face at a ceiling light during thetreatment, then the image pickup device 1 takes image F6 (FIG. 8A). Theimage F6 is stored in the RAM 12 by the image pickup control unit 10 a.However, the recording control unit 10 e does not record the image F6 onthe memory card 9 (FIG. 8B). Similarly, the illumination control unit 10g controls the illumination unit 15 in such a way as to turn theillumination unit 15 OFF or lower the illumination intensity.

When the operator turns his/her eyes back to the treatment targetlocation, the image F7 that the image pickup control unit 10 a receivesfrom the signal processing unit 7 includes the same main subject as theimage F5 does. Therefore, the compressed data of the image F7 isrecorded on the memory card 9, and is displayed on the display unit 13,and the illumination control unit 10 g brings the illumination unit 15back to normal conditions.

If the acceleration sensor 4 detects the movement of the head of theoperator during the shooting of the video, the first movement detectionunit of the movement detection unit 10 b calculates, from angularvelocities of X, Y, and Z that are output from the acceleration sensor4, the amounts of movement of the image pickup device 1 in theleft-right direction (X-direction), the up-down direction (Y-direction),and the front-back direction (Z-direction). In an edge portion of adetection signal supplied from the acceleration sensor 4, distortion,such as ringing or overshooting/undershooting, occurs. Accordingly, themovement detection unit 10 b takes into account in advance a periodduring which the distortion will attenuate in the edge portion of thedetection signal supplied from the acceleration sensor 4, in setting adelay time; the movement detection unit 10 b therefore calculates theamounts of movement of the image pickup device 1 after the delay timehas passed.

Then, the movement detection unit 10 b determines whether the values ofthe amounts of movement calculated are less than or equal to a presetshake judgment threshold value. The shake judgment threshold value is acriterion for determining whether a blur detected by the accelerationsensor 4 is a degree of movement that is unlikely to affect, the qualifyof the captured images. If the values of the amounts of movementcalculated exceed the shake judgment threshold value, the movementdetection unit 10 b then judges that a “camera shake” has occurred.

If the movement detection unit 10 b judges that a “camera shake” hasoccurred, the movement detection unit 10 b controls the image pickupelement displacement mechanism 5 to move, based on the amounts ofmovement calculated at that time, the image pickup element 3 in adirection of cancelling the blur. For example, when the image pickupdevice 1 is causing a blur in the right direction, the camera shakecorrection unit 10 c controls the image pickup element displacementmechanism 5 to move the image pickup element 3 in the left direction byan amount equivalent to the amount of movement. Therefore, the signalprocessing unit 7 can generate the same image data as when no “camerashake” has occurred. Accordingly, in the image data of each frame thatthe signal processing unit 7 outputs to the image pickup control unit 10a, a “camera, shake” has been corrected. Incidentally, if a “camerashake” is to be mechanically corrected, a correction lens isincorporated into the optical lens 2, and the correction lens is movedby the same amount that the image pickup device 1 has moved in adirection of cancelling the blur. In this manner, a camera shakecorrection mechanism that corrects an optical axis may be used.

In that manner, if the amount of movement that the movement detectionunit 10 b calculates from a detection signal supplied from theacceleration sensor 4 exceeds the threshold value, which is used todetermine whether a “camera shake” has occurred, the camera shakecorrection unit 10 c makes a correction, and the image pickup controlunit 10 a displays, on the display unit 13, an image of image data thatis stored in the Ram 12 and has undergone the image processing, such aswhite balance adjustment.

In that manner, if the movement detection unit 10 b (first movementdetection unit) detects a “camera shake” with the acceleration sensor 4,the camera shake correction unit 10 c corrects the camera shake, and theimage pickup control unit 10 a displays, on the display unit 13, theimages of the image data that are stored in the RAM 12 and haveundergone the image processing, such as white balance adjustment. If themovement detection unit 10 b (second movement detection unit) detects ashift in the shooting of the image pickup device 1 away from thetreatment target location by using the subject recognition unit 101 b,the recording control unit 10 e does not record the image data of imagesat that time on the memory card 9. On the memory card 9, only the videoof how the operator is conducting the treatment is recorded. Therefore,only the video of how the operator is conducting the treatment isrecorded on the memory card 9. Thus, the video is highly effective as arecord of the treatment.

Second Embodiment

According to the second embodiment, the amount of movement iselectronically detected without the use of the acceleration sensor 4 inorder to correct a “camera shake”, and a shift in the shooting directionof the image pickup device 1 away from a subject (treatment targetlocation) is detected. Then, the “camera shake” is electronicallycorrected without the use of the image pickup element displacementmechanism 5.

FIG. 6 is a block diagram showing the schematic configuration of amedical image recording device according to the second embodiment. Thisconfiguration is the same as the embodiment shown in FIG. 1 except thatthe acceleration sensor 4 and the image pickup element displacementmechanism 5 do not exist. However, since the acceleration sensor 4 andthe image pickup element displacement mechanism 5 do not exist, theconfiguration of the control programs stored in the ROM 11 that areexecuted by the CPU 10 is partially altered. A movement detection unit10 b′ and a camera shake correction unit 10 c′ in the CPU 10 of FIG. 6carry out control described below.

That is, the movement detection unit 10 b′ carries out control in such away as to calculate an amount of movement of the image pickup device 1based on an amount of positional shift of a main subject captured byeach of images between frames that are adjacent to each other atintervals of 1/30 seconds, or an amount of positional shift of the mainsubject in a positional-shift image of the main subject captured by eachof images between frames that are close to each other, for example, atintervals of 1/3 seconds.

If the amount of movement calculated by the movement detection unit 10b′ exceeds a threshold value that is used to identify a “camera shake”,the camera shake correction unit 10 c′ generates a synthetic image fromimages of two consecutive or adjacent frames, and controls in such a wayas to output the image data.

In addition to the control described on the image pickup control unit 10a, the image pickup control unit 10 a′ carries out additional control insuch a way as to store the synthetic image data, in which the “camerashake” has been corrected, in the RAM 12.

The operation of the medical image recording device of FIG. 6 will bedescribed. When the release switch of the operation unit 8 is operated,the image pickup control unit 10 a′ starts to shoot a video. The imagepickup control unit 10 a′ sequentially takes in image data of each framefrom the signal processing unit 7.

FIGS. 9A and 10A schematically show images of each frame that is takeninto the image pickup control unit 10 a′ from the signal processing unit7, when images taken by the image pickup device 1 that is put on thehead via the above binocular loupe 20 or headband 21 are output to thesignal processing unit 7 during treatment by the operator. The signalprocessing unit 7 actually generates the image data at a rate of 30frames per second in order to allow the image pickup device 1 to shoot avideo. For ease of explanation, a series of images during the treatmentis simplified in such a way as to only show images of representativeframes.

As in the case of the subject recognition unit 101 b described in FIG.1, the movement detection unit 10 b′ uses a pattern matching method toanalyze the images between previous and subsequent frames of each set ofimage data of each frame that the image pickup control unit 10 a takesin. Then, the movement detection unit 10 b′ extracts the contours of thesubject as feature points, and recognizes an area where the featurepoints overlap with one another as a main subject.

The movement detection unit 10 b′ calculates an amount of a positionalshift in the vertical and horizontal directions on X-Y axes of the mainsubject in each of the images between frames that are adjacent to eachother or in each of the images between frames that are close to eachother. The movement detection unit 10 b′ determines whether thecalculated positional-shift amount (or the amount of movement of theimage pickup device 1) is within a preset range. The lower limit of therange is a threshold value at which the positional shift of the subjectdoes not seem to cause a blur and is judged to be a degree of movementthat is unlikely to affect the quality of the captured images; the upperlimit of the range is a threshold value at which it is determined thatthe shooting direction of the image pickup device 1 has significantlymoved away from the subject (treatment target location). When the valueof the amount of movement calculated is within the preset range, themovement detection unit 10 b′ judges that a “camera shake” has occurred.This range will be referred to as “camera shake detection range” in thedescription of this embodiment.

Image F1′ of a pre-treatment state, which is shown as a representativelinage in FIG. 9A, image F2′, which shows a process of opening theabdomen, and image F3′, which comes after the opening of the abdomen,are significantly different. However, the movement detection unit 10 b′sequentially analyzes images between frames that are adjacent to eachother at intervals of 1/30 seconds during that period, or images betweenframes that are close to each other, for example, at intervals of 1/3seconds, and there are no significant differences between the previousand subsequent frames. Therefore, the movement detection unit 10 b′judges that the image pickup device 1 keeps shooting the same subject.That is, since the calculated positional-shift value is less than orequal to the upper limit of the “camera shake detection range”, themovement detection unit 10 b′ judges that the image pickup device 1keeps shooting the same subject.

During a period in which the movement detection unit 10 b′ judges thatthe image pickup device 1 keeps shooting the treatment target location,the image pickup control unit 10 a′ stores the image data of all framesduring that period, including images F1′ to F3′, in the RAM 12 withoutany change, and carries out image processing, such as white balanceadjustment, color interpolation processing, and aberration correctionprocessing. Then, the image pickup control unit 10 a′ sequentially readsthe image data that is stored in the RAM 12 and has undergone the imageprocessing, and outputs the image data to the display unit 13. The videois displayed on the display unit 13 as a result. FIGS. 9B and 10Bschematically shows the image data of each frame stored in the RAM 12.

The compression and decompression processing unit 10 d compresses, inJPEG, each set of the image data sequentially stored in the RAM 12. Thecompressed image data is transmitted to the memory card 9 and recorded.FIGS. 9C and 10C schematically show the image data recorded on thememory card 9.

When the movement detection unit 10 b′ analyzes the images between theframes and extracts the contours of a subject as feature points, themovement detection unit 10 b′ calculates the amount of movement of theimage pickup device 1 from an amount of positional shift on coordinateaxes of a main subject in both images. Then, if the amount of movementis within the “camera shake detection range”, the movement detectionunit 10 b′ judges that a “camera shake” has occurred.

Suppose that the images F3′ and F4′ in FIG. 9A are images of consecutiveframes. In this case, the main subject has moved in the horizontal(X-axis) direction, and the value of the amount of movement of the imagepickup device 1 calculated by the movement detection unit 10 b′ iswithin the “camera shake detection range”. Therefore, the movement isjudged to be a “camera shake”. At this time, the camera shake correctionunit 10 c′ generates a superimposed synthetic image F4A by calculatingthe averages of coordinates of the main subject in the images F3′ andF4′.

If the movement detection unit 10 b′ detects an image shift, then theimage pickup control unit 10 a′ stores the synthetic image F4A, which iscreated by the camera shake correction unit 10 c, in the RAM 12 (FIG.9B), carries out image processing, such as white balance adjustment,color interpolation processing, and aberration correction processing,and outputs the image data of the synthetic image F4A, which hasundergone the image processing, to the display unit 13. The compressionand decompression processing unit 10 d compresses, in JPEG, the imagedata of the synthetic image F4A. The compressed image data istransmitted to the memory card 9 and is recorded (FIG. 9C). In thatmanner, in the case of the third embodiment, the image pickup elementdisplacement mechanism 5 is not used to optically correct the “camerashake”. Accordingly, the image F4′ on which the “camera shake” hasoccurred is corrected into the image F4A before being displayed on thedisplay unit 13 and recorded on the memory card 9.

For example, if the operator suspends the treatment and turns his/herface to an assistant to give the treatment assistant instructions duringthe shooting by the image pickup device 1, then the image pickup device1 takes an image of the assistant, and the image pickup control unit 10a′ takes in the image data of image F5′ from the signal processing unit7. In such a case, the main subject is different from the one identifiedin the previous frame. Therefore, when the movement detection unit 10 b′detects an image shift between frames by carrying out pattern matching,the value of the amount of movement of the image pickup device 1calculated from the shift is greater than the upper limit of the “camerashake detection range”. As a result, the movement detection unit 10 b′judges that the shooting direction of the image pickup device 1 hasmoved from the subject.

The camera shake correction unit 10 c′ does not carry out a process ofgenerating a synthetic image of images of both frames when the amount ofmovement of the image pickup device 1 is greater than the upper limit ofthe “camera shake detection range”. However, the image pickup controlunit 10 a′ stores the image data in the RAM 12 without any change (FIG.9B), and reads the image data to display on the display unit 13 afterconducting image processing, such as white balance adjustment, colorinterpolation processing, and aberration correction processing; or theimage pickup control unit 10 a′ may stop the real-time displaying of theimages captured by the image pickup device 1, and instead display, as astill image, a previously captured image F4A of the treatment targetlocation taken by the image pickup device 1 on the display unit 13.

When the amount of movement of the image pickup device 1 is greater thanthe upper limit of the “camera shake detection range”, the recordingcontrol unit 10 e′ prohibits the frames that follow from being writtento the memory card 9 (FIG. 9C). The illumination control unit 10 gcontrols the illumination drive unit 14 to halt the supply of power tothe illumination unit 15 or reduce the current supplied to theillumination unit 15.

Even after judging that the shooting direction of the image pickupdevice 1 has changed given that the amount of movement has exceeded theupper limit of the “camera shake detection range”, the movementdetection unit 10 b′ continues the pattern matching process of imagedata of each frame that the image pickup control unit 10 a′ receivesfrom the signal processing unit 7, and makes a determination as towhether the image data resembles that of a main subject (i.e. treatmenttarget location) that appears before the amount of movement exceeds theupper limit of the “camera shake detection range”. If the movementdetection unit 10 b detects that a main subject recognized by thesubject recognition unit 101 b resembles a main subject that appearsbefore the shooting direction of the image pickup device 1 moves, thenthe movement detection unit 10 b judges that the operator has resumedthe treatment. Accordingly, the image F6′ and other images that comeafter the resumption of the treatment are compressed by the compressionand decompression processing unit 10 d. The compressed image data aresequentially recorded on the memory card 9 by the recording control unit10 e (FIG. 10C). The illumination control unit 10 g controls theillumination drive unit 14 to resume the supply of power to theillumination unit 15 or bring the amount of current supplied to theillumination unit 15 back to a normal level.

This embodiment, too, has a time-lag period of 0.2 to 0.5 seconds, forexample, as described above. As a result, if the operator temporarilyturns his/her face away from the treatment target location beforeimmediately moving the face back to the treatment target location, animage taken by the image pickup device 1 of a location other than wherethe treatment is being carried out may not be displayed on the displayunit 13. The recording control unit 10 e may wait for the time-lagperiod to pass before controlling the stop of writing of image data tothe memory card 9; the illumination control unit 10 g may wait for thetime-lag period to pass before controlling in such a way as to stop thesupply of power to the illumination unit 15 or reduce the currentsupplied to the illumination unit 15.

When the operator turns his/her face at a ceiling light during thetreatment, then the image pickup device 1 takes image F7′ (FIG. 10A).The image F7′ is stored in the RAM 12 by the image pickup control unit10 a′ (FIG. 10B). However, the recording control unit 10 e does notrecord the image F7′ on the memory card 9 (FIG. 10C). When the operatorturns his/her eyes back to the subject, the image F8′ that the imagepickup device 1 outputs includes the same main subject as the image F6′does. Therefore, the compressed data of the image F6 is recorded on thememory card 9.

In the image F9′ of a frame that follows the image F8′, the position ofthe main subject has moved in the up-down (Y-direction) compared withthe image F8′. The movement detection unit 10 b detects an image shift,and judges that a “camera shake” has occurred if the value of the amountof movement of the image pickup device 1 calculated from the shift iswithin the “camera shake detection range”. At this time, the camerashake correction unit 10 c generates a superimposed synthetic image F9Aby calculating the averages of coordinates of the main subject in theimages F8′ and F9′. The image data of the synthetic image F9A is storedin the RAM 12 (FIG. 10B), and the compressed image data thereof isrecorded on the memory card 9 (FIG. 10C).

In this manner, as for the image data of frames between the image 9′ andthe image F10′, when the movement detection unit 10 b′ is not detectinga “camera shake”, the images of image data that are stored in the RAM 12by the image pickup control unit 10 a′ and have undergone the imageprocessing such as white balance adjustment are displayed on the displayunit 13. If a “camera shake” is detected, the image data of a syntheticimage generated from the image data of previous and subsequent framesundergoes the image processing, and is stored in the RAM 12 anddisplayed on the display unit 13.

The image data of an image that does not cover a main subject by themovement detection unit 10 b′ is not recorded on the memory card 9.Therefore, only the video of how the operator is conducting thetreatment is recorded on the memory card 9. Thus, the video is highlyeffective as a record of the treatment.

The medical image recording device of that embodiment detects a “camerashake” based on an image shift of two consecutive or adjacent frames ofvideo. Therefore, the medical image recording device can suppress the“camera shake”. When the shooting of the image pickup device 1 hassignificantly deviated from the subject (treatment target location), therecording of captured images of that portion is stopped. Therefore, onlyvalid recorded video can be saved.

While the present invention has been described in detail, the presentinvention is not limited to the above embodiments. Various modificationsmay be made based on the spirit of the present invention, and thosemodifications will not be excluded from the scope of the presentinvention.

INDUSTRIAL APPLICABILITY

The present invention relates to a medical image recording device thatshoots progress of treatment by using an image pickup device put on thebody of an operator and which is able to leave, as a record, only aseries of images directly related to the treatment. The presentinvention has industrial applicability.

EXPLANATION OF REFERENCE SYMBOLS

-   1: Image pickup device-   2: Optical lens-   3: Image pickup element-   4: Acceleration sensor-   7: Signal processing unit-   9: Memory card (information recording unit)-   10: CPU-   10 a, 10 a′: Image pickup control unit-   10 b, 10 b′: Movement detection unit-   10 c, 10 c′: Camera shake correction unit-   10 e: Recording control unit-   15: Illumination unit

1. A medical image recording device that shoots by putting, on a body ofan operator conducting medical treatment, an image pickup device thatincludes at least an optical lens and an image pickup element whichgenerates an image pickup signal by photoelectrically converting lightintroduced from a subject via the optical lens during shooting, themedical image recording device comprising: an image pickup control unitthat controls in such a way as to display, on a display unit, a videofrom image data that is generated for each of frames that constitute thevideo based on the image pickup signal; an information recording unitthat sequentially records the image data; a movement detection unit thatsequentially compares the image data between consecutive or adjacentframes, and calculates an amount of movement of the image pickup devicebased on a positional shift of a main subject between the frames; acamera shake correction unit that corrects, when the amount of movementis within a preset range, a positional shift of the video caused by themovement corresponding to the amount of movement; and a recordingcontrol unit that controls stopping of the recording of the image dataon the information recording unit when the amount of movement is greaterthan an upper limit of the range.
 2. The medical image recording deviceaccording to claim 1, wherein the image pickup control unit stops thedisplaying of the video when the amount of movement is greater than theupper limit of the range.
 3. The medical image recording deviceaccording to claim 2, wherein the image pickup control unit stops thedisplaying of the video after a predetermined time-lag period has passedsince the movement detection unit detects that the amount of movement isgreater than the upper limit of the range.
 4. The medical imagerecording device according to claim 2, wherein the image pickup controlunit controls in such a way as to display, as a still image, the imagedata of the frame that appears immediately before the amount of movementexceeds the upper limit of the range, after the displaying of the videois stopped.
 5. The medical image recording device according to claim 1,wherein the recording control unit controls resumption of recording ofthe image data by the information recording unit after the amount ofmovement exceeds the upper limit of the range and after a main subjectdetected by the movement detection unit comes to resemble the mainsubject that appears immediately before the amount of movement exceedsthe upper limit of the range.
 6. The medical image recording deviceaccording to claim 2, wherein the image pickup control unit controlsresumption of displaying of the video after the amount of movementexceeds the upper limit of the range and after a main subject detectedby the movement detection unit comes to resemble the main subject thatappears immediately before the amount of movement exceeds the upperlimit of the range.
 7. The medical image recording device according toclaim 1, comprising an illumination unit that emits light to thesubject, wherein, when the amount of movement is greater than the upperlimit of the range, the illumination unit stops the emission of thelight or lowers the illumination intensity.
 8. The medical imagerecording device according to claim 7, wherein the illumination unitstops the emission of the light or lowers the illumination intensityafter a predetermined time-lag period has passed since the movementdetection unit detects that the amount of movement exceeds the upperlimit of the range.
 9. The medical image recording device according toclaim 7, wherein the illumination unit resumes the emission of the lightor increases the illumination intensity after the amount of movementexceeds the upper limit of the range and after a main subject detectedby the movement detection unit comes to resemble the main subject thatappears immediately before the amount of movement exceeds the upperlimit of the range.
 10. The medical image recording device according toclaim 1, wherein the camera shake correction unit generates, when theamount of movement is within the range, corrected image data bycombining the image data of a plurality of consecutive or adjacentframes.
 11. A medical image recording device that shoots by putting, ona body of an operator conducting medical treatment, an image pickupdevice that includes at least an optical lens and an image pickupelement which generates an image pickup signal by photoelectricallyconverting light introduced from a subject via the optical lens duringshooting, the medical image recording device comprising: an image pickupcontrol unit that controls in such a way as to display, on a displayunit, a video from image data that is generated for each of frames thatconstitute the video based on the image pickup signal; an informationrecording unit that sequentially records the image data; an accelerationsensor that detects movement of the image pickup device; a firstmovement detection unit that calculates an amount of movement of theimage pickup device based a detection signal of the acceleration sensor;a camera shake correction unit that controls in such a way as to cancela blur in the video caused by the movement corresponding to the amountof movement calculated by the first movement detection unit; a secondmovement detection unit that sequentially compares the image databetween consecutive or adjacent frames, and calculates an amount ofmovement of the image pickup device from a positional shift of a mainsubject between the frames; and a recording control unit that controlsstopping of the recording of the image data when the amount of movementcalculated by the second movement detection unit is greater than orequal to a preset threshold value.
 12. The medical image recordingdevice according to claim 11, wherein the first movement detection unittakes into account in advance a period during which distortionattenuates in an edge portion of a detection signal of the accelerationsensor, in setting a delay time, and calculates the amount of movementafter the delay time has passed.
 13. The medical image recording deviceaccording to claim 11, wherein the image pickup control unit stops, whenthe amount of movement calculated by the second movement detection unitis greater than or equal to the threshold value, the displaying of thevideo.
 14. The medical image recording device according to claim 13,wherein the image pickup control unit stops the displaying of the videoafter a predetermined time-lag period has passed since detecting thatthe amount of movement calculated by the second movement detection unitis greater than or equal to the threshold value.
 15. The medical imagerecording device according to claim 13, wherein the image pickup controlunit displays, as a still image, the image data that appears immediatelybefore the amount of movement calculated by the second movementdetection unit becomes greater than or equal to the threshold value,after the displaying of the video is stopped.
 16. The medical imagerecording device according to claim 11, wherein the recording controlunit controls resumption of recording of the image data by theinformation recording unit after the amount of movement calculated bythe second movement detection unit becomes greater than or equal to thethreshold value and after a main subject detected by the second movementdetection unit comes to resemble the main subject that appearsimmediately before the amount of movement exceeds the threshold value.17. The medical image recording device according to claim 13, whereinthe image pickup control unit controls resumption of displaying of thevideo after the amount of movement calculated by the second movementdetection unit becomes greater than or equal to the threshold value andafter a main subject detected by the second movement detection unitcomes to resemble the main subject that appears immediately before theamount of movement exceeds the threshold value.
 18. The medical imagerecording device according to claim 11, comprising an illumination unitthat emits light to the subject, wherein, when the amount of movementcalculated by the second movement detection unit becomes greater than orequal to the threshold value, the illumination unit stops the emissionof the light or lowers the illumination intensity.
 19. The medical imagerecording device according to claim 18, wherein the illumination unitresumes the emission of the light or increases the illuminationintensity after the amount of movement calculated by the second movementdetection unit exceeds the threshold value and after a main subjectdetected by the second movement detection unit comes to resemble themain subject that appears immediately before the amount of movementexceeds the threshold value.